Fix MKV files not Playing on PLEX

Plex is a great tool and media centre where you can play all your files across the devices. These include movies, music, audio, videos, and more. Apart from that, you can also watch free movies, shows, live TV channels, DVR, and even listen to music for free. It is easily one of the best recommendable tools to most users. Another highlight of Plex is that you can download it on Android, iOS, Windows, Mac, Chromecast, Smart TVs, and more. The only noticeable misses are the Amazon Fire Stick and Roku lineup of streaming devices.

That aside, Plex also offers Plex Pass with some additional features that take your experience to the next level. In general, the membership offers a lot many things. Here is the dedicated article comparing both free and paid versions side by side. In this article, we have addressed the problem in Plex while playing MKV files. To state in simple words, many users have reported that the issue while play MKV files on Plex. So, here are the possible reasons, limitations, and solutions for the above issue.

How to fix MKV files not playing on PLEX:

The first is that to play an MKV file on Plex your source device need to satisfy all the conditions and requirements. For instance, if you choose Direct Play, then the file needs to be encoded in a compatible file container, bitrate, and with proper codecs. In some cases, if the subtitle stream is incompatible, then your device may fail to play that particular file.

On the other hand, for Direct Stream, Plex treats the MKV file as an incompatible file container. For compatible file resolution and media type, Plex tries to extract the original file and repack the content on the fly. In this way, some MKV files may play without any issues on your Plex. To top all of these, Plex also has some NAS device limitations. These may include points such as operating system complexity, processor power, and other device specifications.

Well, you might realise that there is a lot of stuff going on for the MKV files. Fortunately or unfortunately, you may even realise that some MKV files play without any errors while some may give such errors. So, instead of checking for all these conditions, you can simply play the MKV file on your device. If it plays as expected, then you are good to go. In case it doesn’t, then the most feasible solution is to convert these files to MP4 format. There are several tools through which you can do this. Here are some of the options:

  • Cloud Convert:  Apart from file format, you can also change audio codec, aspect ratio, resolution, and more.
  • Convert Files: The simple tool for file conversion.
  • VLC Player: The infamous media player can also convert MKV to MP4.


To sum up, MKV files have always been the default option for many movies and other video files. But, seems like this issue may continue with Plex. So, you can either check the compatibility with the above conditions or convert them with the given tools. In either case, hopefully, you will be able to fix the issue.

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Karthik, a tech enthusiast and avid gamer, is a seasoned expert at With a passion for cricket, bowling, and Counter Strike (PC Game), Karthik seamlessly combines his hobbies with his extensive knowledge to assist users in conquering social media apps, software, and devices.